mindmap root((先驱)) forerunner is applicable to anything that serves as a sign, omen, or warning of something to come: the international incident was a ~ to war. precursor applies to a person or thing that paves the way for the success or accomplishment of another: 18th century poets who were ~s of the Romantics. harbinger, herald both apply, chiefly figuratively, to one that proclaims or announces the coming or arrival of a notable event or person: robins, the ~s of spring（harbingers）; the ~ of a new age in medical science.